When to flip coins for shorty's stack?

Is this a bad play? Should I just look for a situation to "try" and get him all in when I know I'm ahead? I did raise to $1 preflop and he reraised to 3.25 like it shows in the HH. No real read. He's not getting into a lot of pots.

Should I have just folded? He has a big hand too often? I can't call for set value...
Ultimate Bet No-Limit Hold'em, $.25 BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver Cards)

Hero ($26.15)
MP ($21.85)
CO ($22)
Button ($28.55)
SB ($9.50)
BB ($5.90)

Preflop: Hero is UTG with http://www.flopturnriver.com/phpBB2/.../smiles/th.gif, http://www.flopturnriver.com/phpBB2/.../smiles/ts.gif.
3 folds, SB completes, BB raises to $3.25, Hero raises to $7.5, SB folds, BB folds.

Final Pot: $11

The HH doesn't show you raising to 1$ btw.

But anyways I think this was good...I have no clue though why the BB didn't call. He has 5.90$ behind, raises to 3.25$, then folds when you reraise?

I think usually there is a big chance the BB would have called your raise and gone all-in here. No clue why he folded here.